1. Field of the Invention
The present invention relates to a jet-propulsion personal watercraft (PWC) which ejects water rearward and planes on a water surface as the resulting reaction.
2. Description of the Related Art
In recent years, so-called jet-propulsion personal watercraft, which is one type of small watercraft, have been widely used in leisure, sport, rescue activities, and the like. The personal watercraft is configured to have a water jet pump that pressurizes and accelerates water sucked from a water intake generally provided on a hull bottom surface and ejects it rearward from an outlet port. Thereby, the personal watercraft is propelled.
In the jet-propulsion personal watercraft, a steering nozzle provided behind the outlet port of the water jet pump is swung either to the right or to the left, to change the ejection direction of the water to the right or to the left, thereby turning the watercraft to the right or to the left.
An engine for driving the water jet pump is mounted in an engine room defined by a deck and a hull of the personal watercraft. An opening is provided in an upper portion of the deck so as to communicate with the engine room. Through the opening, inspection and maintenance of the engine in the engine room are carried out. When overhauling the engine, an exhaust pipe, an air-intake pipe, and an air cleaner box, and the like, which are connected to the engine, are removed from the engine, and then the engine is taken out of the engine room through the opening.
In a straddle-type personal watercraft, a straddle-type seat is typically mounted above the opening. Thus, the width of the opening in the above-mentioned deck is limited by the rider""s straddle position, that is, by the dimensions of a seat suitable to be straddled by a rider and possibly a passenger. In addition, in a stand-up type personal watercraft, the size of the opening provided in the deck is limited in view of rigidity of a body of the watercraft.
For the above reasons, it is hard to remove the exhaust pipe, the air-intake pipe, and the like from the engine mounted in the engine room and to take the engine out of the engine room, through the opening. When removing the exhaust pipe, the air-intake pipe, and the like, from the engine, there are many portions which are difficult to see from outside through the opening. Therefore, the removing operation is troublesome and takes a long time. The same is true when the engine is re-mounted into the engine room through the opening, and the exhaust pipe, the air-intake pipe, and the like are connected to the engine mounted in the engine room.
Because of a limited internal space of the body of the personal watercraft, the engine is sometimes mounted in the engine room such that its cylinder is inclined. In a four-cycle engine mounted in such an inclined state, portion where the cylinder head cover is fastened to the cylinder head by means of bolts is sometimes invisible from outside through the opening of the deck. For regular inspection of a valve mechanism covered by the cylinder head cover, the cylinder head cover needs to be removed from the cylinder head, which operation is troublesome.
The present invention addresses the above condition, and an object of the present invention is to provide a personal watercraft capable of easily removing and mounting an engine and easily performing maintenance of the engine mounted in a body of the watercraft.
According to the present invention, there is provided a jet-propulsion personal watercraft including a water jet pump ejecting water rearward to propel the watercraft as a reaction of the ejecting water, comprising: an engine for driving the water jet pump; an engine room surrounded by a hull and a deck, for containing the engine, the engine room having an opening for maintenance in an upper portion thereof; an exhaust pipe connected to the engine; an air-intake pipe connected to the engine; and an oil filter mounted to the engine, and the engine including: an exhaust pipe connecting face to which the exhaust pipe is connected; an air-intake pipe connecting face to which the air-intake pipe is connected; and an oil filter mounting face to which the oil filter is mounted, wherein the exhaust pipe connecting face, the air-intake pipe connecting face, and the oil filter mounting face are located in the opening as seen from a direction in which the opening is opened.
In the jet-propulsion personal watercraft so constituted, connected end potions of the exhaust pipe and the air-intake pipe, and the mounted portion of the oil filter can be easily checked from outside through the opening formed in the upper portion of the engine room. Therefore, the exhaust pipe, the air-intake pipe, and the oil filter can be easily mounted to/removed from the engine in the engine room. Besides, the engine without the exhaust pipe, the air-intake pipe, and the oil filter, can be put into/taken out of an inside of a body of the watercraft through the opening while keeping the exhaust pipe connecting face, the air-intake pipe connecting face, and the oil filter mounting face out of touch with the periphery of the opening. In such a personal watercraft, inspection and maintenance of the engine can be easily carried out.
Preferably, the oil filter mounting face may be formed such that a normal direction of the oil filter mounting face substantially corresponds with a direction orthogonal to the direction in which the opening is opened or is angled upward with respect to the direction orthogonal to the direction in which the opening is opened. In the jet-propulsion personal watercraft so constituted, the mounting face of the oil filter is visible from outside through the opening of the deck. Therefore, the oil filter can be easily mounted/removed in the state in which the engine is mounted in the engine room.
Preferably, the exhaust pipe connecting face and the air-intake pipe connecting face may be formed such that normal directions of the exhaust pipe connecting face and the air-intake pipe connecting face substantially correspond with a direction orthogonal to the direction in which the opening is opened or are angled upward with respect to the direction orthogonal to the direction in which the opening is opened. In this structure, both the exhaust pipe connecting face and the air-intake pipe connecting face are visible from outside through the opening of the deck. Therefore, the exhaust pipe and the air-intake pipe can be easily mounted/removed in the state in which the engine is mounted in the engine room.
Preferably, the exhaust pipe connecting face, the air-intake pipe connecting face, and the oil filter mounting face may be formed such that normal directions of the exhaust pipe connecting face, the air-intake pipe connecting face, and the oil filter mounting face substantially correspond with a direction orthogonal to the direction in which the opening is opened or are angled upward with respect to the direction orthogonal to the direction in which the opening is opened. In this structure, the exhaust pipe connecting face, the air-intake pipe connecting face, and the oil filter mounting face are visible from outside through the opening of the deck. Therefore, the exhaust pipe, the air-intake pipe, and the oil filter can be easily mounted/removed in the state in which the engine is mounted in the engine room.
Preferably, the engine may be configured to be smaller than the opening as seen from the direction in which the opening is opened, in a state in which the exhaust pipe, the air-intake pipe, and the oil filter are removed from the engine. In this structure, the engine can be put into/taken out of the inside of the body of the watercraft through the opening.
The engine may be contained in the engine room such that a cylinder is inclined with respect to a vertical direction and the exhaust pipe connecting face, the air intake pipe connecting face, and the oil filter mounting face are located in the opening as seen from the direction in which the opening is opened. In the jet-propulsion personal watercraft so constituted, even when the engine is contained in the engine room such that the cylinder is inclined, the connected end portions of the exhaust pipe and the air-intake pipe, and the mounted portion of the oil filter can be easily checked from outside through the opening in the upper portion of the engine room. Therefore, the exhaust pipe, the air-intake pipe, and the oil filter can be easily mounted to/removed from the engine contained in the engine room. Consequently, in the jet-propulsion personal watercraft, inspection and maintenance of the engine can be easily carried out.
Preferably, the exhaust pipe connecting face and the air-intake pipe connecting face may be formed such that normal directions of the exhaust pipe connecting face and the air-intake pipe connecting face substantially correspond with a direction orthogonal to the direction in which the opening is opened or are angled upward with respect to the direction orthogonal to the direction in which the opening is opened. In this structure, even when the engine is contained in the engine room such that its cylinder is inclined, both of the exhaust pipe connecting face and the air-intake pipe connecting face are easily visible from outside through the opening of the deck.
Preferably, the exhaust pipe connecting face, the air-intake pipe connecting face, and the oil filter mounting face may be formed such that normal directions of the exhaust pipe connecting face, the air-intake pipe connecting face, and the oil filter mounting face substantially correspond with a direction orthogonal to the direction in which the opening is opened or are angled upward with respect to the direction orthogonal to the direction in which the opening is opened. In this structure, the exhaust pipe connecting face, the air-intake pipe connecting face, and the oil filter mounting face are visible from outside through the opening of the deck.
Preferably, the exhaust pipe connecting face, the air-intake pipe, and an air filter mounted to a tip end portion of the air-intake pipe may be located in the opening as seen from the direction in which the opening is opened. In this structure, the engine mounting to and removing from the engine room can be easily carried out.
Preferably, a cylinder head cover accommodating a valve mechanism inside thereof may be fastened to a cylinder head of the engine by means of a screw means and the screw means is configured such that its center axis passes through an inside of the opening. In this structure, the cylinder head cover can be easily attached/detached by mounting/removing the screw means, because a tool such as a wrench can reach the screw means such as the bolt for fastening the cylinder head cover to the cylinder head, through the opening. Therefore, in the state in which the engine is mounted in the engine room, inspection, adjustment and the like of a valve mechanism accommodated in the cover can be easily carried out.
According to the present invention, there is further provided a jet-propulsion personal watercraft including a water jet pump ejecting water rearward to propel the watercraft as a reaction of the ejecting water, comprising: an engine for driving the water jet pump; and an engine room surrounded by a hull and a deck, for containing the engine, the engine room having an opening for maintenance in an upper portion thereof and containing the engine with a cylinder inclined with respect to a vertical direction; and a cylinder head cover fastened to a cylinder head of the engine by means of a screw means, wherein the screw means is configured such that its center axis passes through an inside of the opening.
In the jet-propulsion personal watercraft so constituted, the cylinder head cover can be easily attached/detached by mounting/removing the screw means, because the tool such as the wrench can reach the screw means such as the bolt for fastening the cylinder head cover to the cylinder head, through the opening. Therefore, in the state in which the engine is mounted in the engine room, inspection, adjustment and the like of the valve mechanism accommodated in the cover can be easily carried out.
Preferably, the screw means may be configured such that its center axis is inclined with respect to a face at which the cylinder head cover is attached to the cylinder head.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.